Use-after-free in Linux kernel - CVE-2026-53262

Vulnerability identifier: #VU135484

CSH Severity: Low

CVSS v4: 7.3 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-53262

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service or execute arbitrary code.

The vulnerability exists due to use-after-free in pppol2tp_ioctl() when processing ioctl requests while a concurrent socket close frees the associated l2tp_session after a controllable sleep during copy_from_user(). A local user can trigger a userfaultfd-assisted page fault sleep and race a socket close to dereference a stale session pointer to cause a denial of service or execute arbitrary code.

Exploitation requires local access to issue the ioctl and induce the race condition.

Linux kernel
openEuler
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
kernel-headers
kernel-source
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf
python3-perf-debuginfo

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel - update to 5.10.0-327.0.0.228
bpftool - update to 5.10.0-327.0.0.228
bpftool-debuginfo - update to 5.10.0-327.0.0.228
kernel-debuginfo - update to 5.10.0-327.0.0.228
kernel-debugsource - update to 5.10.0-327.0.0.228
kernel-devel - update to 5.10.0-327.0.0.228
kernel-headers - update to 5.10.0-327.0.0.228
kernel-source - update to 5.10.0-327.0.0.228
kernel-tools - update to 5.10.0-327.0.0.228
kernel-tools-debuginfo - update to 5.10.0-327.0.0.228
kernel-tools-devel - update to 5.10.0-327.0.0.228
perf - update to 5.10.0-327.0.0.228
perf-debuginfo - update to 5.10.0-327.0.0.228
python3-perf - update to 5.10.0-327.0.0.228
python3-perf-debuginfo - update to 5.10.0-327.0.0.228

• https://git.kernel.org/stable/c/62f327e287cf7b595ae3f73ba72f5cd2a9e9f39f
• https://git.kernel.org/stable/c/78cdfdca88cbf731a92f3b9ee5427c633dd94e28
• https://git.kernel.org/stable/c/a213a8950414c684999dcf03edeea6c46ede172e
• https://git.kernel.org/stable/c/e251d4cdfc725c9e7d686161e3b775a0e7d95053

• Use-after-free in Linux kernel l2tp
• openEuler 22.03 LTS SP4 update for kernel